/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtMultimedia module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
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** $QT_END_LICENSE$
**
****************************************************************************/

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of other Qt classes.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <QtCore/qcoreapplication.h>
#include "qaudiooutput_alsa_p.h"

QT_BEGIN_NAMESPACE

//#define DEBUG_AUDIO 1

static const int minimumIntervalTime = 50;

QAudioOutputPrivate::QAudioOutputPrivate(const QByteArray &device, const QAudioFormat& audioFormat):
    settings(audioFormat)
{
    bytesAvailable = 0;
    handle = 0;
    ahandler = 0;
    access = SND_PCM_ACCESS_RW_INTERLEAVED;
    pcmformat = SND_PCM_FORMAT_S16;
    buffer_frames = 0;
    period_frames = 0;
    buffer_size = 0;
    period_size = 0;
    buffer_time = 100000;
    period_time = 20000;
    totalTimeValue = 0;
    intervalTime = 1000;
    audioBuffer = 0;
    errorState = QAudio::NoError;
    deviceState = QAudio::StopState;
    audioSource = 0;
    pullMode = true;
    resuming = false;
    opened = false;

    QStringList list1 = QString(QLatin1String(device)).split(QLatin1String(":"));
    m_device = QByteArray(list1.at(0).toLocal8Bit().constData());

    timer = new QTimer(this);
    connect(timer,SIGNAL(timeout()),SLOT(userFeed()));
}

QAudioOutputPrivate::~QAudioOutputPrivate()
{
    close();
    disconnect(timer, SIGNAL(timeout()));
    QCoreApplication::processEvents();
    delete timer;
}

QAudio::Error QAudioOutputPrivate::error() const
{
    return errorState;
}

QAudio::State QAudioOutputPrivate::state() const
{
    return deviceState;
}

void QAudioOutputPrivate::async_callback(snd_async_handler_t *ahandler)
{
    QAudioOutputPrivate* audioOut;

    audioOut = static_cast<QAudioOutputPrivate*>
        (snd_async_handler_get_callback_private(ahandler));

    if((audioOut->deviceState==QAudio::ActiveState)||(audioOut->resuming))
        audioOut->feedback();
}

int QAudioOutputPrivate::xrun_recovery(int err)
{
    int  count = 0;
    bool reset = false;

    if(err == -EPIPE) {
        errorState = QAudio::UnderrunError;
        err = snd_pcm_prepare(handle);
        if(err < 0)
            reset = true;

    } else if((err == -ESTRPIPE)||(err == -EIO)) {
        errorState = QAudio::IOError;
        while((err = snd_pcm_resume(handle)) == -EAGAIN){
            usleep(100);
            count++;
            if(count > 5) {
                reset = true;
                break;
            }
        }
        if(err < 0) {
            err = snd_pcm_prepare(handle);
            if(err < 0)
                reset = true;
        }
    }
    if(reset) {
        close();
        open();
        snd_pcm_prepare(handle);
        return 0;
    }
    return err;
}

int QAudioOutputPrivate::setFormat()
{
    snd_pcm_format_t pcmformat = SND_PCM_FORMAT_S16;

    if(settings.sampleSize() == 8) {
        pcmformat = SND_PCM_FORMAT_U8;

    } else if(settings.sampleSize() == 16) {
        if(settings.sampleType() == QAudioFormat::SignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                pcmformat = SND_PCM_FORMAT_S16_LE;
            else
                pcmformat = SND_PCM_FORMAT_S16_BE;
        } else if(settings.sampleType() == QAudioFormat::UnSignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                pcmformat = SND_PCM_FORMAT_U16_LE;
            else
                pcmformat = SND_PCM_FORMAT_U16_BE;
        }
    } else if(settings.sampleSize() == 24) {
        if(settings.sampleType() == QAudioFormat::SignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                pcmformat = SND_PCM_FORMAT_S24_LE;
            else
                pcmformat = SND_PCM_FORMAT_S24_BE;
        } else if(settings.sampleType() == QAudioFormat::UnSignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                pcmformat = SND_PCM_FORMAT_U24_LE;
            else
                pcmformat = SND_PCM_FORMAT_U24_BE;
        }
    } else if(settings.sampleSize() == 32) {
        if(settings.sampleType() == QAudioFormat::SignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                pcmformat = SND_PCM_FORMAT_S32_LE;
            else
                pcmformat = SND_PCM_FORMAT_S32_BE;
        } else if(settings.sampleType() == QAudioFormat::UnSignedInt) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                pcmformat = SND_PCM_FORMAT_U32_LE;
            else
                pcmformat = SND_PCM_FORMAT_U32_BE;
        } else if(settings.sampleType() == QAudioFormat::Float) {
            if(settings.byteOrder() == QAudioFormat::LittleEndian)
                pcmformat = SND_PCM_FORMAT_FLOAT_LE;
            else
                pcmformat = SND_PCM_FORMAT_FLOAT_BE;
        }
    } else if(settings.sampleSize() == 64) {
        if(settings.byteOrder() == QAudioFormat::LittleEndian)
            pcmformat = SND_PCM_FORMAT_FLOAT64_LE;
        else
            pcmformat = SND_PCM_FORMAT_FLOAT64_BE;
    }

    return snd_pcm_hw_params_set_format( handle, hwparams, pcmformat);
}

QIODevice* QAudioOutputPrivate::start(QIODevice* device)
{
    if(deviceState != QAudio::StopState)
        deviceState = QAudio::StopState;

    errorState = QAudio::NoError;

    // Handle change of mode
    if(audioSource && pullMode && !device) {
        // pull -> push
        close();
        audioSource = 0;
    } else if(audioSource && !pullMode && device) {
        // push -> pull
        close();
        delete audioSource;
        audioSource = 0;
    }

    if(device) {
        //set to pull mode
        pullMode = true;
        audioSource = device;
        deviceState = QAudio::ActiveState;
    } else {
        //set to push mode
        if(!audioSource) {
            audioSource = new OutputPrivate(this);
            audioSource->open(QIODevice::WriteOnly|QIODevice::Unbuffered);
        }
        pullMode = false;
        deviceState = QAudio::IdleState;
    }

    open();

    emit stateChanged(deviceState);

    return audioSource;
}

void QAudioOutputPrivate::stop()
{
    if(deviceState == QAudio::StopState)
        return;
    deviceState = QAudio::StopState;
    close();
    emit stateChanged(deviceState);
}

bool QAudioOutputPrivate::open()
{
    if(opened)
        return true;

#ifdef DEBUG_AUDIO
    QTime now(QTime::currentTime());
    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :open()";
#endif
    timeStamp.restart();
    elapsedTimeOffset = 0;

    int dir;
    int err=-1;
    int count=0;
    unsigned int freakuency=settings.frequency();

    QString dev = QLatin1String(m_device.constData());
    if(!dev.contains(QLatin1String("default"))) {
        dev = QString(QLatin1String("default:CARD=%1")).arg(QLatin1String(m_device.constData()));
    }
    // Step 1: try and open the device
    while((count < 5) && (err < 0)) {
        err=snd_pcm_open(&handle,dev.toLocal8Bit().constData(),SND_PCM_STREAM_PLAYBACK,0);
        if(err < 0)
            count++;
    }
    if (( err < 0)||(handle == 0)) {
        errorState = QAudio::OpenError;
        deviceState = QAudio::StopState;
        return false;
    }
    snd_pcm_nonblock( handle, 0 );

    // Step 2: Set the desired HW parameters.
    snd_pcm_hw_params_alloca( &hwparams );

    bool fatal = false;
    QString errMessage;
    unsigned int chunks = 8;

    err = snd_pcm_hw_params_any( handle, hwparams );
    if ( err < 0 ) {
        fatal = true;
        errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_any: err = %1").arg(err);
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_rate_resample( handle, hwparams, 1 );
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_rate_resample: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_access( handle, hwparams, access );
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_access: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = setFormat();
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_format: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_channels( handle, hwparams, (unsigned int)settings.channels() );
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_channels: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_rate_near( handle, hwparams, &freakuency, 0 );
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_rate_near: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_buffer_time_near(handle, hwparams, &buffer_time, &dir);
        if ( err < 0 ) {
            fatal = true;
                errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_buffer_time_near: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_period_time_near(handle, hwparams, &period_time, &dir);
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_period_time_near: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params_set_periods_near(handle, hwparams, &chunks, &dir);
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_periods_near: err = %1").arg(err);
        }
    }
    if ( !fatal ) {
        err = snd_pcm_hw_params(handle, hwparams);
        if ( err < 0 ) {
            fatal = true;
            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params: err = %1").arg(err);
        }
    }
    if( err < 0) {
        qWarning()<<errMessage;
        errorState = QAudio::OpenError;
        deviceState = QAudio::StopState;
        return false;
    }
    snd_pcm_hw_params_get_buffer_size(hwparams,&buffer_frames);
    buffer_size = snd_pcm_frames_to_bytes(handle,buffer_frames);
    snd_pcm_hw_params_get_period_size(hwparams,&period_frames, &dir);
    period_size = snd_pcm_frames_to_bytes(handle,period_frames);
    snd_pcm_hw_params_get_buffer_time(hwparams,&buffer_time, &dir);
    snd_pcm_hw_params_get_period_time(hwparams,&period_time, &dir);

    // Step 3: Set the desired SW parameters.
    snd_pcm_sw_params_t *swparams;
    snd_pcm_sw_params_alloca(&swparams);
    snd_pcm_sw_params_current(handle, swparams);
    snd_pcm_sw_params_set_start_threshold(handle,swparams,period_frames);
    snd_pcm_sw_params_set_stop_threshold(handle,swparams,buffer_frames);
    snd_pcm_sw_params_set_avail_min(handle, swparams,period_frames);
    snd_pcm_sw_params(handle, swparams);

    // Step 4: Prepare audio
    if(audioBuffer == 0)
        audioBuffer = new char[snd_pcm_frames_to_bytes(handle,buffer_frames)];
    snd_pcm_prepare( handle );
    snd_pcm_start(handle);

    // Step 5: Setup callback and timer fallback
    snd_async_add_pcm_handler(&ahandler, handle, async_callback, this);
    bytesAvailable = bytesFree();

    // Step 6: Start audio processing
    timer->start(period_time/1000);

    timeStamp.restart();
    elapsedTimeOffset = 0;
    errorState  = QAudio::NoError;
    totalTimeValue = 0;
    opened = true;

    return true;
}

void QAudioOutputPrivate::close()
{
    deviceState = QAudio::StopState;
    timer->stop();

    if ( handle ) {
        snd_pcm_drain( handle );
        snd_pcm_close( handle );
        handle = 0;
        delete [] audioBuffer;
        audioBuffer=0;
    }
    if(!pullMode && audioSource) {
        delete audioSource;
        audioSource = 0;
    }
    opened = false;
}

int QAudioOutputPrivate::bytesFree() const
{
    if(resuming)
        return period_size;

    if(deviceState != QAudio::ActiveState && deviceState != QAudio::IdleState)
        return 0;
    int frames = snd_pcm_avail_update(handle);
    if((int)frames > (int)buffer_frames)
        frames = buffer_frames;

    return snd_pcm_frames_to_bytes(handle, frames);
}

qint64 QAudioOutputPrivate::write( const char *data, qint64 len )
{
    // Write out some audio data
    if ( !handle )
        return 0;
#ifdef DEBUG_AUDIO
    qDebug()<<"frames to write out = "<<
        snd_pcm_bytes_to_frames( handle, (int)len )<<" ("<<len<<") bytes";
#endif
    int frames, err;
    int space = bytesFree();
    if(len < space) {
        // Just write it
        frames = snd_pcm_bytes_to_frames( handle, (int)len );
        err = snd_pcm_writei( handle, data, frames );
    } else {
        // Only write space worth
        frames = snd_pcm_bytes_to_frames( handle, (int)space );
        err = snd_pcm_writei( handle, data, frames );
    }
    if(err > 0) {
        totalTimeValue += err*1000000/settings.frequency();
        resuming = false;
        errorState = QAudio::NoError;
        deviceState = QAudio::ActiveState;
        return snd_pcm_frames_to_bytes( handle, err );
    } else
        err = xrun_recovery(err);

    if(err < 0) {
        close();
        errorState = QAudio::FatalError;
        deviceState = QAudio::StopState;
        emit stateChanged(deviceState);
    }
    return 0;
}

int QAudioOutputPrivate::periodSize() const
{
    return period_size;
}

void QAudioOutputPrivate::setBufferSize(int value)
{
    if(deviceState == QAudio::StopState)
        buffer_size = value;
}

int QAudioOutputPrivate::bufferSize() const
{
    return buffer_size;
}

void QAudioOutputPrivate::setNotifyInterval(int ms)
{
    if(ms >= minimumIntervalTime)
        intervalTime = ms;
    else
        intervalTime = minimumIntervalTime;
}

int QAudioOutputPrivate::notifyInterval() const
{
    return intervalTime;
}

qint64 QAudioOutputPrivate::totalTime() const
{
    return totalTimeValue;
}

void QAudioOutputPrivate::resume()
{
    if(deviceState == QAudio::SuspendState) {
        int err = 0;

        if(handle) {
            err = snd_pcm_prepare( handle );
            if(err < 0)
                xrun_recovery(err);

            err = snd_pcm_start(handle);
            if(err < 0)
                xrun_recovery(err);

            bytesAvailable = (int)snd_pcm_frames_to_bytes(handle, buffer_frames);
        }
        resuming = true;
        if(pullMode)
            deviceState = QAudio::ActiveState;
        else
            deviceState = QAudio::IdleState;

        errorState = QAudio::NoError;
        timer->start(period_time/1000);
        emit stateChanged(deviceState);
    }
}

QAudioFormat QAudioOutputPrivate::format() const
{
    return settings;
}

void QAudioOutputPrivate::suspend()
{
    if(deviceState == QAudio::ActiveState || deviceState == QAudio::IdleState || resuming) {
        timer->stop();
        deviceState = QAudio::SuspendState;
        errorState = QAudio::NoError;
        emit stateChanged(deviceState);
    }
}

void QAudioOutputPrivate::userFeed()
{
    if(deviceState == QAudio::StopState || deviceState == QAudio::SuspendState)
        return;
#ifdef DEBUG_AUDIO
    QTime now(QTime::currentTime());
    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :userFeed() OUT";
#endif
    if(deviceState ==  QAudio::IdleState)
        bytesAvailable = bytesFree();

    deviceReady();
}

void QAudioOutputPrivate::feedback()
{
    QMetaObject::invokeMethod(this, SLOT(updateAvailable()), Qt::QueuedConnection);
}

void QAudioOutputPrivate::updateAvailable()
{
#ifdef DEBUG_AUDIO
    QTime now(QTime::currentTime());
    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :updateAvailable()";
#endif
    bytesAvailable = bytesFree();
}

bool QAudioOutputPrivate::deviceReady()
{
    if(pullMode) {
        int l = 0;
        int chunks = bytesAvailable/period_size;
        if(chunks==0) {
            bytesAvailable = bytesFree();
            return false;
        }
#ifdef DEBUG_AUDIO
        qDebug()<<"deviceReady() avail="<<bytesAvailable<<" bytes, period size="<<period_size<<" bytes";
        qDebug()<<"deviceReady() no. of chunks that can fit ="<<chunks<<", chunks in bytes ="<<period_size*chunks;
#endif
        int input = period_frames*chunks;
        if(input > (int)buffer_frames)
            input = buffer_frames;
        l = audioSource->read(audioBuffer,snd_pcm_frames_to_bytes(handle, input));
        if(l > 0) {
            // Got some data to output
            if(deviceState != QAudio::ActiveState)
                return true;
            write(audioBuffer,l);
            bytesAvailable = bytesFree();

        } else if(l == 0) {
            // Did not get any data to output
            bytesAvailable = bytesFree();
            if(bytesAvailable > snd_pcm_frames_to_bytes(handle, buffer_frames-period_frames)) {
                // Underrun
                errorState = QAudio::UnderrunError;
                deviceState = QAudio::IdleState;
                emit stateChanged(deviceState);
            }

        } else if(l < 0) {
            close();
            errorState = QAudio::IOError;
            emit stateChanged(deviceState);
        }
    } else
        bytesAvailable = bytesFree();

    if(deviceState != QAudio::ActiveState)
        return true;

    if((timeStamp.elapsed() + elapsedTimeOffset) > intervalTime) {
        emit notify();
        elapsedTimeOffset = timeStamp.elapsed() + elapsedTimeOffset - intervalTime;
        timeStamp.restart();
    }
    return true;
}

qint64 QAudioOutputPrivate::clock() const
{
    if(!handle)
        return 0;

    if (deviceState == QAudio::StopState)
        return 0;

    snd_pcm_status_t* status;
    snd_pcm_status_alloca(&status);

    snd_timestamp_t t1,t2;
    if( snd_pcm_status(handle, status) >= 0) {
        snd_pcm_status_get_tstamp(status,&t1);
        snd_pcm_status_get_trigger_tstamp(status,&t2);
        t1.tv_sec-=t2.tv_sec;

        signed long l = (signed long)t1.tv_usec - (signed long)t2.tv_usec;
        if(l < 0) {
            t1.tv_sec--;
            l = -l;
            l %= 1000000;
        }
        return ((t1.tv_sec * 1000)+l/1000);
    } else
        return 0;
    return 0;
}

void QAudioOutputPrivate::reset()
{
    if(handle)
        snd_pcm_reset(handle);

    stop();
}

OutputPrivate::OutputPrivate(QAudioOutputPrivate* audio)
{
    audioDevice = qobject_cast<QAudioOutputPrivate*>(audio);
}

OutputPrivate::~OutputPrivate() {}

qint64 OutputPrivate::readData( char* data, qint64 len)
{
    Q_UNUSED(data)
    Q_UNUSED(len)

    return 0;
}

qint64 OutputPrivate::writeData(const char* data, qint64 len)
{
    int retry = 0;
    qint64 written = 0;
    if((audioDevice->deviceState == QAudio::ActiveState)
            ||(audioDevice->deviceState == QAudio::IdleState)) {
        while(written < len) {
            int chunk = audioDevice->write(data+written,(len-written));
            if(chunk <= 0)
                retry++;
            written+=chunk;
            if(retry > 10)
                return written;
        }
    }
    return written;

}

QT_END_NAMESPACE
